Vat dyestuffs of the anthraquinone series



Patented May 10, 1927.

UNITED STATES ALFRIED seine? o'rrENBAcH-oN-THE-MMN, GERMANY, AssIGnon r0 enassnnm 1,627,73'8 PATENT OFFICE;

DYESTUFF CORPORATION, OF NEW YORK, N. Y., A CORPORATION OEIDELA WABE.

VAT DYESTUFFS or THE ANTHRAQUINONE SERIES.

No Drawing. Application filed December 8, 1925, Serial No. 74,172, and in Gei-many December 22, 1924.

in which the anthraq'uinone nucleimay b substituted. The dyestuffs in their dry ulverized form are green to orange-yel ow powders,- soluble in concentrated sulfuric icid giving red-colored solutions and in boiling hot nitrobenzol giving orange-yellow p lue hydrosulfite colored solutions. From a vat, they dye cotton reddish to greenish tints which are fast to alkali.

The new dyestuffs .may be obtained by treating the pyrazolanthron yellow bodies with formaldehyde in a sulfuric acid solution. The chemical constitution of the dyestnfis is not known.

Besides the pyrazolanthron yellow itself, there may be used its derivatives, for example, the chlorine s'ubstitution products.

The following examples illustrate the invention: (1) 1 part of paraformaldehyde and 5 parts of pyrazolanthron yellow are dissolved 1n parts of 66 Be. sulfuric acid. The solution is stirred for about a week at room temperature and then poured .mto water,

and the resulting dyestufi is separated, washed and dried. The product is a green-' ish yellow powder which dissolves in concentrated sulfuric .acid giving a-red colored solution and in boiling hot nitrobenzol, one part of the dyestuif to one hundredcand' fifty parts of the nitrobenzol, giving an orange-yellow colored solution without fluorescence. The dyestuif is crys'talllzable from the nitrobenzol solution. A lukewarm blue vatof the dyestufl dyes cotton a blue Itint which upon exposure to the air changesto a brightgreenish yellow co1or,.the resulting dyeingsibeing fast light and alkali.

(2) 1 part of formaldehyde and 5 parts of pyrazolanthron yellow are dissolved in 50 parts of oleum and the solution stirred for several hours at 50 C. By pouring the resulting solution into "water and separating the dyestufi' in the usual way, one obtains a dyestuif which in its dry'form is an orange-colored powder soluble in sulfuric acid with a red color and in boiling'hot nitrobenzol (1:150) with an orange-yellow color.- The nitrobenzol solution is without fluoresence. The dyestufi' may be crystallized from the nitrobenzol solution. A blue warm vat of the dyestuff dyes cotton blue tints which-upon exposure to the air change to a bright reddish yellow fast to alkali.

' 3) If a sulfuric acid solution, such as is described in Example 1, is kept warm for several hours at approximately 50. there is obtained a dyestuif possessing characteristics similar to those described in Example 2, but which dyes cotton blue tints which on exosure to the air change into a bright goldyellow fast to alkali. On subjecting the dye-- stuff to several recrystallizations, it can be separated into the dyestuif of Example 1 which dyes a greenish yellow, and the dyestuff of Example 2 which dyes a reddish yellow.

I claim as l anthraquinoneseries fast to talkali, which in which the anthraquinone nucleus may be further substituted, which dyestuffs in a dry pulverized form are greenish yellow to orange yellow, soluble in sulfuric acid giving red colored solutions and in boiling. hot J nitrobenzol giving orange yellow colored solutions and which dye cotton frombluehydrosulfite vats reddish to greemsh-yellow tints which are fast toalkali.

- I l. v As new'pl'oducis, vat dyestufis of the 2. As new products, vat dyestuffs of the anthraquinone series which are fast to alkali,

which are reaction products of formaldehyde on pyrazolanthron yellow, which dye- 5 stufi's in a dry' pulverized form are greenish yellow to orange yellow, are soluble in sulfuric acid giving red colored solutions and in boiling hot nitrobenzol giving orange yellow colored solutions, and which dye cot- 1 ton from blue hydrosulfite vats reddish to greenish yellow tints which are fast to alkali 3. Process of preparing new vat dyestuffs of the anthraquinone series which are fast to alkali, consisting in allowing forxnalde hyde to act upon pyrazolanthron yellow compounds in sulfuric acid solution.

4. Process of preparing new vat dyestuffs of the anthraquinone series which are fast to alkali, conslsting in allowing formaldehyde to act upon pyrazolanthron yellow in sulfuric acid solution.

In testimony whereof, I afiix my si nature.

7 ALFRED OLL. 

